ADAMS ARMS PISTON KIT MICRO ADJ. PISTOL .750 GAS BLOCK FEATURES: Patented One-Piece Bolt Carrier P Series Micro Block – Adjustable (5 Settings – 100%/74%/53%/32%/11%) Bolt Spring Drive Rod with Bushing and Spring Installation Instruction Card Our Piston Kits No Longer Require the Receiver Bushing or Installation Dowel A short stroke free floating piston system. Is Self-Cleaning. Carbon and gases are expelled forward, away from operator. Corrosive resistant coating processes. Harmonics are not transferred into the barrel. Doesn’t vent directly to atmospheric pressure; this eliminates flash signature and super sonic crack which is optimal for night vision and suppresses fire. Has a Lifetime Warranty.